The Athlon 64 X2 is the first dual-core desktop CPU designed by AMD. It was designed from scratch as native dual-core by using an already multi-CPU enabled Athlon 64, joining it with another functional core on one die and connect both via a shared dual-channel memory controller/north bridge and additional control logic. The initial versions are based on the E-stepping model of the Athlon 64 and, depending on the model, have either 512 or 1024 KB of L2 Cache per core. The Athlon 64 X2 is capable of decoding SSE3 instructions (except those few specific to Intel's architecture).In June 2007, AMD released low-voltage variants of their low-end 65 nm Athlon 64 X2, named Athlon X2. The Athlon X2 processors feature reduced TDP of 45 Watts